Brief Introduction of Working Roll Performance of Packaging Steel Strip Rough Mill

Brief Introduction of Working Roll Performance of Packaging Steel Strip Rough Rolling Mill
　　The working conditions of the front work roll (R) for rough rolling are similar to those of the blooming mill roll, so it must have strong toughness, wear resistance and thermal cracking resistance. Most of the material used for the rolls is special cast steel. The hardness was initially HS530-40. However, due to the requirements of wear resistance and surface roughness, the hardness gradually increased. At present, many rolling mills use rolls with a hardness of about HS40-55.
　　The rough surface of the work roll after the rough rolling (RW) is the biggest problem. Since the occurrence of thermal cracking will promote the surface roughness, it is required to use a material with good heat-resistant cracking performance. As for the development of materials, it was initially based on high-alloy cast iron rolling series. Since 1965, the number of half-steel rolls has increased, and the hardness has reached HS45-55. Some factories also use high-hardness HS60-75 Alloy cast iron rolls. Recently, we are striving to use special cast semi-steel rolls.
　　Finishing front work rolls (FW) Compared with roughing work rolls, the rough surface of the rolls caused by the peeling off of the roll skin and the sticking of the oxide scale on the rolls will affect the surface quality of the finished product3; The impact is greater. On the other hand, the work rolls in the front stage of finishing rolling have less wear than the work rolls in the back stage of rough rolling. The former has less wear when rolling the same tonnage, but it requires greater strip steel biting ability, so it is generally used Semi-steel rolls with hardness of about HS50. Recently, the semi-steel rolls or specially cast semi-steel rolls with better wear resistance and surface roughness resistance have become popular.
　　 Finishing-rolling post-work rolls (FHW) Finishing-rolling post-work rolls are used in the final stage of rolling and have a direct impact on the quality and surface condition of the finished product. Because the wear of the roll will cause the deterioration of the accuracy of the plate thickness, the shape of the strip and the surface of the strip, people attach great importance to the wear resistance of the roll (including keeping the roll surface smooth). The roll was originally made of high-alloy chilled fine-grained cast iron with a hardness of HS78-86. Since 1965, centrifugal casting rolls have been tried. The characteristic of this type of roll is that although the diameter of the roll gradually becomes smaller during repeated use, its hardness rarely decreases. Recently, almost all of these rolls have been used.